Towards Cloning a Russian Wheat Aphid Resistance Gene: New Genomic Tools and Resources

Positional cloning in bread wheat (Triticum aestivum L.) is hampered by enormous genome size (~ 17 Gbp) and polyploid character of the wheat genome. These obstacles can be largely overcome by dissecting the genome into particular chromosome arms by flow-cytometric sorting. This strategy enables construction of subgenomic BAC libraries, physical maps as well as gaining shotgun sequences of particular chromosome arms, which are favorable resources for cloning genes in the hexaploid wheat. We used the chromosome-based approach to facilitate cloning of a Russian wheat aphid resistance gene Dn2401 located on the short arm of chromosome 7D. New genomic tools and resources such as GenomeZipper, high-density Ae. tauschii linkage map as well as sequence assemblies of group 7 chromosomes were employed for a highly focused marker development and search for candidate genes within a 2.5 cM interval on 7DS.This work has been supported by the Ministry of Education, Youth and Sports of the Czech Republic and the European Regional Development Fund (Operational Programme Research and Development for Innovations No. CZ.1.05/2.1.00/01.0007) and Australian Research Council (grant award LP0882095).